A friend of mine once described this as a "critical hit chance" (ala video games). There's not much chance of a 'critical hit' if you're just hanging around hom

A friend of mine once described this as a "critical hit chance" (ala video games). There's not much chance of a 'critical hit' if you're just hanging around home, for example. But if you're on the road, stopping in at a random pub for dinner? There's that chance something special happens. Sometimes it might be better to trade the option with higher average damage for one that is more volatile, because you might get lucky at just the right moment.